XL Touch Screen Goes Crazy!

[NoWhereMan]

Yes, it's me again! I just keep having troubles.

In an earlier post of mine I talked about having to reformat and restore this thing. After doing so, I've noticed the screen doesn't respond to touch as well at it did (never was great but now...). I viewed the details of a trip and began to zoom in and drag the screen and things went crazy. With my finger on the left side of the screen and attempting to drag it to the right, it quickly zoomed out and put me in the Pacific Ocean looking down on Hawaii. Another attempt zoomed in to the closet level. I assume this has something to do with restoring after the catastrophe or could it be the demise of the touch screen?

I read (I'll have to reread) here something about recalibrating but this is so far off it almost sounds like a failure. Maybe it's just time to go for the 2505.

 

[canderson]

For reasons that I have never been able to pry out of a resistive touch screen engineer, these units DO often become less responsive over time. This is particularly true when the screen is not used often -- e.g., a unit that spends a fair bit of its time sitting in a drawer and not being poked all the time. It's my personal feeling that the polyester top layer becomes less compliant over time, but that's just a guess.

When you attempt to perform other functions on the unit - for example, entering an address - do the right 'buttons' respond when you press the screen? Just trying to see if perhaps there's any merit to the calibration suggestion or not.

 

[NoWhereMan]

For reasons that I have never been able to pry out of a resistive touch screen engineer, these units DO often become less responsive over time. This is particularly true when the screen is not used often -- e.g., a unit that spends a fair bit of its time sitting in a drawer and not being poked all the time. It's my personal feeling that the polyester top layer becomes less compliant over time, but that's just a guess.

When you attempt to perform other functions on the unit - for example, entering an address - do the right 'buttons' respond when you press the screen? Just trying to see if perhaps there's any merit to the calibration suggestion or not.

I did a factory reset and it seems to be working better. Before I performed the reset, I looked at the info screen and noticed the last screen data calibration field was scrambled. It displayed one strange looking character followed by 4/5 numbers then 2 letters. This unit came from the factory (4 years ago) with a calibration file; I never created one. Now I can't seem to get back the the info screen no matter how long I hold down the button. Was curious to see what it is now.

 

[NoWhereMan]

I forgot to answer your question. It did respond incorrectly to the touch- sometimes. For example: when selecting a city it might pick the one above it and it would sometimes pick the wrong letters. After the reformat it was real bad.

 

[canderson]

The unit doesn't come with a calibration file from the factory. That's part of the basic load of the system that you never see or access, and provides the default values. A calibration file is added after the fact by a user to allow for correction of the default that is built into the unit.

Anyway, it sounds like that data was corrupted at some point, and you may have to use a calibration file to get this unit to behave. Makes me wonder if that is all that was corrupted!

To access that diag screen again, you just have to hold the power down past the boot until the white on black text screen comes up again. You should see the logo and hear the drums, and then keep holding for a while longer and it should give you that screen.

 

[NoWhereMan]

Interresting. Are you sure about the calc file? This unit came factory sealed in the box from Walmart. Holding down the button now gets me to the navigation screen. No logo, no drums. Doesn't matter how long I hold it.

 

[canderson]

Yes, I am absolutely sure about the calibration file. As new, there is no cal.txt or calib.txt file on the unit (what it was called changed over the years). At manufacture, the unit is tested and default calibration values are determined to match the characteristics of the touch screen that was picked for the unit.

Adding the file after the fact causes the contents of the file to override the default settings that were programmed into the unit at the factory.